A hostname is a unique name by which a computing device may be identified on a network. Hostnames are used to simplify access to computing devices by enabling users to use unique names instead of addresses to access these devices. A hostname is typically translated into an Internet address by a Domain Name System (DNS ) server.
Use of hostnames in mobile computing environments has introduced additional considerations. As mobile computing devices (hereafter mobile nodes) become increasingly popular, various protocols have been developed to address mobile computing requirements. For example, to enable mobile node users to move from one location to another (roam) while continuing to maintain their connectivity to the same network, the Internet Engineering Task Force (IETF) has promulgated roaming standards (Mobile IPv4, IETF RFC 3344, August 2002, hereafter Mobile IPv4, and Mobile IPv6, IETF Mobile IPv6, Internet Draft draft-ietf-mobileip-ipv6-19.txt. (Work In Progress), October 2002, hereafter Mobile IPv6).
Mobile IPv4 is currently the predominant standard, and many networks today are Mobile IPv4 compliant. Mobile IPv4 introduced the concept of Network Access Identifiers (NAIs). NAIs may be used in either Mobile IPv4 or Mobile IPv6 compliant networks to uniquely identify a mobile node. While a mobile node is typically identified by one hostname, it may also be associated with more than one NAI. Similar to hostnames, NAIs may also be translated into an Internet address by a DNS server.